The Milky Way
The Milky Way (also known as The Galaxy) is a barred spiral galaxy that is home to all of the known species in the galaxy with the notable exception of the Precursors. The Milky Way is visible from any position in the galaxy which takes the form of a dim bar of light stretching across the sky to a ring of light around the position of the viewer depending on the location of observation. The galaxy is generally believed to be approximately 100,000 lightyears in diameter, but current observations and mathematical predictions in accordance to advanced probing methods revise the figure to near 150,000 to 180,000 lightyears. All matter in the galaxy orbits around the galactic center which contains the supermassive black hole Sagittarius A*, at on average 220 kilometers per second. A star like Sol takes approximately 250 million years to complete a rotation around the mid-range disk where it is located, though all stars in the galaxy are actually in motion, albeit at a speed that is barely noticeable to the observer in real-time. All of the known types of stars in the universe have numbers in the Milky Way, with the most common being M-class red dwarfs which are small, dim, cool, and long-lived. Some of these stars are nearly as old as the observable universe which suggests that the Milky Way formed not long after the creation of the universe. The Milky Way is orbited by several dwarf galaxies with the more well known of them being the Small and Large Magellanic Clouds, with the Large cloud being known as Path Kethona to the Forerunners, though the closest orbiting of the group is the Sagittarius Dwarf Galaxy, which orbits at 70,000 lightyears, meaning that this spheroid galaxy passes through the galactic frame on its orbit. No known race, save for perhaps the Forerunners or the Precursors have engaged in intergalactic travel, as only the most advanced races have the means of calculating jumps over such a distance, and even then, most recorded sojourns are only to the nearest satellite galaxies. Description The Milky Way is described based on observations from Installation 00 as a barred spiral galaxy. Up until early in the 21st Century, many depictions of the galaxy have taken the form of a pure spiral galaxy. Models were refined after this point to create the concept of the Milky Way being a barred spiral galaxy. This model represents the Milky Way as having a central galactic bulge made up of hot young stars. Two bars of these types of stars typically ranging from B to O-class stretch a distance from the core with the outer arms being populated with cooler stars that have longer lives. Estimates for star population speculate that the Milky Way contains anywhere from between 200 billion to 400 billion stars and approximately 100 billion planets spaced anywhere in between. As red dwarfs are the most populous of all the stellar classes, it is believed that many planets orbit these red dwarfs, though as studies have shown into the 33rd Century, most life-bearing worlds are concentrated between K-class and F-class stars with the G-class of which Sol is one, make up the so-called 'sweet spot' of life production. The Milky Way has several arms which spiral away from the central bulge: the 3-kpa Arm, the Perseus Arm, the Norma Arm, the Outer Arm, the Scutum-Centaurus Arm and the Carina-Sagittarius Arm. In addition to this, there are several 'spurs' or offshoot arms that branch off from the larger of the galactic arms, with one of which being the Orion-Cygnus Arm, commonly just called the Orion Arm or Orion Spur. This is the portion of the galaxy that contains the Sol system and many of the inhabited worlds of Humanity. Several other sentient races that are known to Humanity also have their homes in the Orion Spur, if not the interspace areas between the arms which are still rich in stars, even if it doesn't appear so on a map. The Milky Way is surrounded by a film of energy known as a galactic halo which can be composed of stars that orbit in a spheroid manner around the galaxy not confined to the galactic disk, as well as ionized plasma that extends some distance away from the galactic rim that is not visible to the naked eye. The Milky Way is located within the Local Group of galaxies that comprises 54 galaxies in (relatively speaking) close proximity to one another. The largest of which closest to the Milky Way is the Andromeda Galaxy, which is located two million lightyears from the Milky Way, though it appears larger than the moon in a clear sky. The Andromeda galaxy is on a collision course for the Milky Way and scientists believe that the impact will take place in two to four billion years. There will be no 'collision' in the strictest sense, but stars will be ripped from their current position with some being flung into intergalactic space and others being pulled into the new massive galaxy speculated to be named Milkomeda. However, there is very little danger of this happening anytime soon. Like all galaxies, the Milky Way rotates around a supermassive black hole known as Sagittarius A*. This central vortex creates the gravitational force that pulled all of the gas and dust into the place where it is now. Sagittarius A* is speculated to be a primordial black hole that formed close to 13 billion years ago when the universe was newly formed. As it shows no signs of evaporating from Hawking Radiation due to its size, it is likely to be the center of galactic gravity either until it is impacted by Andromeda's black hole and merges, or is thrown into intergalactic space from a near-miss where it could last until it evaporates 100 trillion years into the future. Alternate Versions Because of the Extrauniversal Space exploration initiative that was enacted by the UNSC in 3234, there is scientific interest in what alternate versions of the Milky Way appear as. Out of over a thousand versions analyzed by the Frontier Corps, the vast majority keep the barred spiral shape. There are a few exceptions with some versions of the Milky Way appearing as a collection of bubbles appearing to be centered around white holes, the theorized opposite of a black hole in which matter is deposited into space. Galaxies appear to be a common physical phenomenon in many EUS spaces with many universes obeying the same physical laws that the Home Universe obeys. Different versions of the galaxy may have had different histories and as such, stellar position is not uniform, though many stars appear to be similar to the Home Universe version, though technically all stars are new stars. In EUS-0, the universe hosting the world of Mobius, nearby stars are named the same as their Home Universe counterparts for the sake of simplicity, though the farther away one is, the differences are far more pronounced and stars are given a catalog typically with a designator of what universe it was found in, followed by the date of its discovery, sector, and then sequential number of discovery followed by the stellar class of the object. For example, a star found in EUS-0 may bear the moniker of: EUS0.06013235.001.0001-A2IV Stars formed through different laws of physics are often difficult to catalog as the scanning equipment needs to 'adjust' to the physics of the new world it passes into, and some laws are so alien from the Home Universe that the equipment is outright destroyed as the object cannot safely transition to the physical laws of the Alternate Milky Way galaxy. The labeling method for galaxies follows a similar pattern to stars, instead of sector, the type of galaxy is labeled in its stead. In the example below, a new barred spiral galaxy has been located and has been cataloged for study. EUS1830.06013235.BSG.0001 List of Appearances * All works of the Chaos Chronicles Category:Locations Category:Galaxy